The evaluation of central visual fatigue in computer terminal users by visual evoked potentials]

Visual evoked potentials (VEPs) were recorded in a group of 20 operators aged 25-45 years during two sessions, before and after a 5-hour work at computer terminals, in order to assess visual system fatigue. The outcomes were referred to the norms established for the age-matched population of 30 subjects not exposed to professional contact with computers. Most of the examined operators suffered various complaints concerning not only the organ of vision but the central nervous system as well. VEPs were elicited by means of monocular stimulation using the reversal checkerboard pattern and recorded simultaneously from the scalp electrodes placed over the right and the left cerebral hemisphere. Only recording acquired after finishing of a working day demonstrated significant statistically abnormalities of the VEPs waveforms, which suggests their transient character. The changes mentioned above included prolongation of peaks P100 and N2 latency with concomitant attenuation of their amplitudes and a decrease of the correlation coefficient values for the recordings from the hemispheres. The preliminary findings presented in this paper seem to justify a conclusion that the non-invasive VEPs method can be considered as the objective indicator of the central visual fatigue induced by the workload at computer terminals.     

Health problems of the stomatognathic system in the Polish population receiving stomatological health care. 2. Raising environment and education

On the basis of examination of 4872 preschool children and children from elementary schools and university students a usually unfavourable health condition of the stomatognathic system was found, but this condition was relatively least bad in elementary school children. A much better condition of the stomatognathic system was demonstrated in children attending preschool clinic than pedodontic clinics. The obtained results show that the aim of oral hygiene outlined by the WHO by the year 2000 can be achieved only by a part of children and adolescents.     

Atypical clinical image of myopathy with abnormal mitochondria (MAM) in our cases

Two peculiar cases of mitochondrial myopathy are presented. In the first case the diagnostic difficulties are discussed stressing especially the differentiation of the myopathy from myasthenia. In the second cases polyneuropathy signs were evident, which is extremely rare in this myopathy.     

Activity of certain salivary enzymes in school children exposed to excessive concentrations of lead and cadmium

The purpose of the study was assessment of the effect of an environment contaminated with heavy metals on the activity of certain enzymes of mixed saliva. The activity was determined of total acid phosphatase and phosphatase resistant to tartrate and formaldehyde, alkaline phosphatase, alanine and aspartate aminotransferase, and alpha-amylase. The studied material comprised 110 saliva samples obtained from three groups of children aged 8 years. Group I of 21 children lived in Szopienice, group II of 30 children lived in Miasteczko Slaskie. In both these localities the children were exposed to mean daily concentrations, above the permitted ones, mainly of lead compounds, in lower degree to cadmium and zinc compounds. Environment contamination in Szopienice was greater than in Miasteczko Slaskie. Group III of 59 children living in Lubowice served as controls. In that town the permissible concentrations of these compounds were not exceeded. Statistical analysis of these results showed that the activity of total acid phosphatase in groups I and II, that is in the contaminated areas, was highly significantly greater than in the control group. The activity of alkaline phosphatase was raised only in the saliva in group I. No differences were found in the activity of alpha-amylase and aminotransferases.     

Clinical significance of anismus in encopresis

Treatments designed to relieve paradoxical contraction of the anal sphincters during defecation (anismus) have had limited success in children with encopresis. This has raised doubts as to the clinical relevance of this diagnosis in childhood as anorectal dysfunction. Our aim was to determine whether, in patients who had treatment-resistant encopresis, the presence of electromyographic anismus was associated with increased faecal retention. Sixty-eight children with soiling (mean age 8.7 ± 2.06 years) were assessed by clinical examination, abdominal radiography and then with anorectal manometry. Patients with electromyographic anismus (n= 32; 47%) had significantly increased radiographic rectal faecal retention and were significantly less likely to be able to defecate water-filled balloons. There were no significant differences in response to prior therapy, history of primary encopresis, behavioural adjustment or in sociodemographic data. Our results suggest that electromyographic anismus is associated with obstructed defecation and faecal retention.     

Net uptake of gamma-aminobutyric acid by a high-affinity system of rat brain synaptosomes

Rat brain synaptosomes isolated on discontinuous Ficoll gradient carry out rapid net uptake of gamma-aminobutyric acid through a high-affinity system (Km = 6.25 microM; Vmax = 1.2 nmol/min per mg of protein). The uptake of the labeled neurotransmitter is dependent on sodium concentration and is abolished by addition of 40 microM veratridine or 0.5 mM 2,4-diaminobutyric acid. Homoexchange in this preparation accounts for less than 10% of the measured uptake of gamma-amino[14C]butyric acid. It is concluded that the high-affinity transport exhibits properties characteristic of a system that is responsible for the rapid removal of gamma-aminobutyric acid from the synaptic cleft after neuronal transmission.     

The lack of influence of normobaric oxygen on the generalized Shwartzman reaction in the rabbit

The influence of breathing oxygen on the generalized Shwartzman reaction in the rabbit was studied. We did not observe any effect of oxygen in the results of the ethanol gelation test, on the fibrinogen level in plasma nor on the fibrinolytic activity in euglobulins and in the renal cortex and outer medulla. The endotoxin-induced intraglomerular fibrin deposition was also unchanged in oxygen-breathing rabbits. It is concluded that the mechanism of the generalized Shwartzman reaction is unaffected by breathing normobaric oxygen.     

(N-Barbituryl)phenyl- and cyclohexylalkanoic acids and some of their derivatives as potential anti-inflammatory agents.

A series of p-(N-barbituryl)phenyl- and cyclohexylalkanoic acids and their esters were synthesized. The preliminary pharmacological screening using the carrageenin, xylene and cotton tests revealed strong anti-inflammatory activity of several compounds in some of the tests performed, compound (Ij) being active in all the tests.